The measurement of glycosylated hemoglobin is probably the best means of assessing glucose control over time in diabetics. It now appears there is inverse correlation between the control of glucose metabolism and complications of the disease in that well controlled diabetics do much better. The currently available assay systems for quantitating glycosylated hemoglobin are bulky, time consuming and expensive and therefore are ideal candidates for replacement with a monoclonal antibody based immunoassay. To that end antibodies from hybridoma clones derived from fusions of spleen cells from mice immunized with the glycosylated hemoglobin are currently being evaluated and plans are to develop additional hybridomas as part of Phase I. During Phase II a two-site immunometric assay will be developed for quantitation of glycosylated hemoglobin for use in the clinical laboratory.